I am surprised that no one has replied to your post. A collector rather than a gunsmith, I can speak only in generalities and perhaps offer considerations.
The rifle you propose would of course require a rechambering, opening the bolt face (to accommodate the larger dim diameter of the magnum cartridge) as well as magazine and presumably feed ramp alterations. Then such as the 'cock on closing' issue might well be addressed too. What about the stock and perhaps a reblue? Sights? It is also possible that for safety reasons, the barrel should be replaced. Someone else in this forum such as Chuck in Denver would be the expert's expert on all this.
These matters translate into economic considerations which in my mind would tend to strongly mitigate against such work. The chief one is the costs versus the 'investment return'. It seems most likely you would spend far more than the worth of the result. As a utility sporter, this would clearly seem the case although the potential loss would be mitigated by less total investment. Still hardly a satisfactory perspective going into a transaction. As an intensive sporting conversion, probably only a greater loss potential.
A large portion of this analysis too would involve your choice of chambering. The 308 Norma Mag is an interesting cartridge, but there are today likely better and certainly far more economical cartridges available. Your choice is approaching the 'exotic' cartridge realm. This would also play into the resulting value of the conversion. There is likely a quite limited market for a P17 so chambered.
Of course if you personally have the time, talents, equipment and place to work, that would affect strongly any 'bottom line'. Yet no matter the calculation, short of craftsmanship verging on artisan, your 'creation' would probably be an unwise investment.
The days of truly cheap military rifles worthy and capable of reasonable sporting conversion are largely reflections of a past era. The availability of good, modern commercial rifles as well as the cost of parts and especially skilled labor; all these things have largely precluded military conversions in any categories other other than economy handy rifles (of which your proposal doesn't reasonably qualify) or 'labors of love'. I have a few in which others have disproportionately invested their efforts. I acquired them for quite moderate investments. Sometimes far better to simply enjoy the fruits of the work of others.
Just my take and... Good luck!